Isolation and identification of Pseudomonas aeruginosa phages

Pseudomonas aeruginosa is an opportunistic pathogen that stands out with its high antibacterial resistance, rapid adaptation to environmental conditions, and biofilm production. Bacteriophages are viruses that infect bacterial cells and inhibit them. This study aimed to isolate and characterize phages effective against P. aeruginosa. Within the scope of the study, isolation and purification of 8 different P. aeruginosa strains and 15 phages were provided. The latent periods of the phages were found to be between 5 min and 30 min; and their burst sizes were found to be between 10 and 200 POB/cell. The adsorption rates of these phages were found to be between 4.6×10-7 and 1.62×10-8 mL/min. The adsorption rates were found to be the lowest 87% and the highest 100%. The host scale and EOP values of the phages were determined. While the phages did not infect different types of bacteria used in the study, they also showed lytic effects on a different species, P. brassicacearum. Again, within the scope of the thesis, it was determined that the phages showed high stability in different temperature, pH and NaCl containing environments. In addition, different rates of antibiofilm activity of the phages were determined. DNAs of the phages were isolated and cut with SmaI, NdeI, EcoRI, EcoRV, XhoI restriction enzymes. According to the results of RFLP analysis, 8 different phages were selected. According to TEM micrographs, these phages were found to be podovirus, their head diameters were between 42.6 nm and 69.6 nm, and their tail lengths were between 10 nm and 41.6 nm. The mixture formed from these phages was tested against P. aeruginosa in water, skim milk and lettuce samples. The phage mixture completely inhibited the bacteria in water and skim milk at MOI 100. Inhibition was not obtained in the lettuce sample. In the study, P. aeruginosa strains were exposed to the phage mixture for 48 hours and at the end of the period, it was determined that the strains gained different levels of sensitivity to streptomycin, ciprofloxacin, tetracycline and penicillin. KEYWORDS: Pseudomonas aeruginosa, Bacteriophage, Phage Therapy, Antibiofilm